From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47186) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X5jDh-00058C-Tk for qemu-devel@nongnu.org; Fri, 11 Jul 2014 18:23:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X5jDb-0002I1-Ou for qemu-devel@nongnu.org; Fri, 11 Jul 2014 18:23:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12484) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X5jDb-0002Hb-Go for qemu-devel@nongnu.org; Fri, 11 Jul 2014 18:23:03 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s6BMN1jL021547 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 11 Jul 2014 18:23:02 -0400 From: Max Reitz Date: Sat, 12 Jul 2014 00:23:03 +0200 Message-Id: <1405117387-25539-1-git-send-email-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH 0/4] block: Warn about usage of growing formats over non-growable protocols List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Stefan Hajnoczi , Max Reitz Some image formats (e.g. qcow2) require the underlying file to grow on write accesses, but this is in fact not supported by all protocols (e.g. nbd does not). If such a format requiring file growth is used non-read-only over a protocol which does not support this, a warning should be issued. This warning is issued for example whenever one tries to export a qcow2 image over nbd-server and use the export from qemu. We could make this an error, but I decided not to in order to retain "compatibility" (although if this warning is emitted, the user should have already complained about I/O errors on write accesses, so it's questionable what behavior this should be compatible to). While at it, make BDS.growable actually indicate what it is (as far as I understood) supposed to: Whether the BDS supports writes beyond the end of the disk size (which then automatically increase that disk size). Max Reitz (4): block: Correct bs->growable block: Introduce requires_growing_file iotests: Make some qemu-io commands read-only iotests: Skip read and write in 040 for length=0 block.c | 11 +++++++++++ block/blkdebug.c | 2 ++ block/blkverify.c | 2 ++ block/cow.c | 1 + block/iscsi.c | 2 ++ block/nbd.c | 2 ++ block/qcow.c | 1 + block/qcow2.c | 2 ++ block/qed.c | 1 + block/raw_bsd.c | 1 + block/vdi.c | 2 ++ block/vhdx.c | 2 ++ block/vmdk.c | 1 + block/vpc.c | 2 ++ include/block/block_int.h | 4 ++++ tests/qemu-iotests/040 | 18 +++++++++++------- tests/qemu-iotests/072 | 9 ++++++++- tests/qemu-iotests/072.out | 1 + tests/qemu-iotests/089 | 2 +- 19 files changed, 57 insertions(+), 9 deletions(-) -- 2.0.1